Drive, including an electric motor and a transmission, and method for producing a drive

ABSTRACT

A drive includes an electric motor, having a rotor shaft rotatably mounted in a motor housing by bearing(s), and a transmission, having a transmission housing including a housing part and a cover part connected together. A bayonet guide region is arranged on, and projects into a recess of, the housing part. An adapter flange is connected to the motor housing in a torsion-resistant manner and includes a lug region engageable behind the bayonet guide region. The recess is restricted in the circumferential direction by a holding fin provided on the housing part, extending from a bearing receptacle of the bearing of the input shaft of the transmission in the radial direction and is restricted counter to the circumferential direction by a further holding fin provided on the housing part, extending from a bearing receptacle of the bearing of the input shaft in the radial direction.

FIELD OF THE INVENTION

The present invention relates to a drive that includes an electric motorand a transmission, and to a method for producing a drive.

BACKGROUND INFORMATION

Certain conventional electromotoric drives have an electric motor and atransmission.

German Published Patent Document No. 20 2006 014 231 describes anelectromotoric kitchen appliance having a bayonet lock for an electricmotor and a gear stage.

U.S. Patent Application Publication No. 2015/0349606 describes anelectric device.

German Published Patent Document No. 10 2012 007 958 describes anelectric tool having an intermediate gear.

German Published Patent Document No. 10 2005 030 217 describes anelectric motor and a transmission unit for actuators in a motor vehicle.

German Published Patent Document No. 10 2011 054 958 describes a housingof an actuator for the accommodation of an electric motor.

Chinese Published Patent Document No. 102280963 describes an electricdrive.

German Published Patent Document No. 10 2012 202 049 describes anelectric machine.

German Published Patent Document No. 10 2009 044 589 describes a methodfor improving the structural quality of bearing pedestals in a cylinderblock.

SUMMARY

Example embodiments of the present invention provide a drive havingsimplified production.

According to example embodiments of the present invention, a driveincludes an electric motor and a transmission. A housing of thetransmission has a housing part and a cover part, which are connected toeach other, in particular. A bayonet guide region is provided on thehousing part. The electric motor has a rotor shaft and a motor housing,and the rotor shaft is rotatably mounted in the motor housing with theaid of at least one bearing. An adapter flange is connected to the motorhousing in a torsion-resistant manner, and the adapter flange has a lugregion, in particular a bayonet nose, in particular for an engagementbehind the bayonet guide region. The bayonet guide region projects intoa recess of the housing part, and the recess is restricted in thecircumferential direction by a holding fin provided on the housing part,which extends from a bearing receptacle of the bearing of the inputshaft of the transmission, in particular in relation to the axialdirection of the input shaft, in the radial direction. For example, therecess is restricted counter to the circumferential direction by afurther holding fin provided on the housing part, which extends from abearing receptacle of the bearing of the input shaft in the radialdirection.

This offers the advantage that the holding fin stabilizes a bearingreceptacle and for this purpose, extends radially away from the bearingreceptacle to the edge region of the housing part. This makes itpossible to achieve a stabilization of the bearing receptacle and also arestriction of the movement range of the bayonet nose. A compactconfiguration is therefore achievable as well inasmuch as the bayonetnose engages behind the bayonet guide region and is thereby guided in akeyed connection.

According to example embodiments, the bayonet guide region touches thefurther holding fin, in which case the bayonet guide region, the furtherholding fin and the bearing receptacle are integrally arranged,especially molded, in particular as one part. This offers the advantagethat the further holding fin and the bayonet guide region may be formedon the housing part in an integral fashion, and thus are able to beproduced in one piece.

According to example embodiments, the housing of the transmission has ahousing part and a cover part, which are connected to each other, inparticular, a shaft of the transmission is mounted via bearings, a firstbearing of the bearings is accommodated in a bearing receptacle that isdeveloped on the housing part, and a second bearing of the bearings isaccommodated in a bearing receptacle that is provided on the cover part.A respective sealing element, in particular a sealing element made ofrubber or an elastomeric material, in particular an O-ring, is situatedbetween a respective bearing receptacle and a respective bearing, thesealing elements being elastically deformed, so that the respectivesealing element presses the respective bearing against a step of theshaft in each case, in particular, such that the bearings of the shaftare preloaded with respect to each other.

This has the advantage that the bearings are preloaded relative to eachother, or in other words, are pressed against a respective step of theshaft. The contact pressure is the spring force that is generated by theelastic deformation of the seals. The particular spring force generatedby the elastic deformation of the seal accommodated in the housing partis directed counter to the particular spring force that is generated bythe elastic deformation of the seal accommodated in the cover part.

According to example embodiments of the present invention, the seals notonly provide sealing of the interior space of the transmission from theexternal environment but also function as spring elements for thepreloading of the bearings relative to one another. This makes itpossible so save additional preloading elements and thereby simplifiesthe production.

According to example embodiments, web regions, which are provided on thehousing part and project toward the bearing accommodated in the bearingreceptacle of the housing part, restrict the elastic deformation of theseal, the web regions in particular always being situated at the sameradial distance and/or being spaced apart from one another in thecircumferential direction, and/or the web regions resting against arespective bearing. This offers the advantage that the web regions areable to be produced without additional work because they are produced inthe cast component simply by molding.

According to example embodiments, the housing part has bearingreceptacles, and a bearing seat is provided in each bearing receptacle,the respective bearing seat in particular being provided withinterruptions in the circumferential direction, and bearing surfaceareas are provided on the side facing away from the bearing seat, inparticular the outer side, of the housing part, which are planar and arealigned with one another, in particular, that is to say, the bearingsurface areas are provided, especially situated, in a common plane, inparticular.

This has the advantage that the housing part is able to be produced as acast component but the raw cast has a corresponding roughness.

Impressing the stamping tool with its cylindrical stamps allows for aprecise production. The relative positioning of the bearing seats, inparticular, is able to be produced with high precision because thestamps are jointly situated in a stamping tool. In addition, each one ofthe bearing seats may be produced with a precise fit. To ensure that theimpressing can be carried out in a stable manner, the stable positioningof a working plane is possible on the other side of the housing part.The planar outer surface regions of the housing part are provided forthis purpose.

As a result, a simple production is possible.

According to example embodiments, the cover part has bearingreceptacles, and a separate bearing seat is provided in each bearingreceptacle, the respective bearing seat in particular having aninterrupted development in the circumferential direction, planar bearingsurface areas, which in particular are aligned with one another, beingarranged on the side facing away from the bearing seat, in particularthe outer side, of the cover part, the bearing surface areas thusparticularly being provided, especially situated, in a common plane.This offers the advantage that the cover part is able to be produced asa cast component, the raw cast being correspondingly rough, however.

A precise production is possible by impressing the stamping tool withits cylindrical stamps. More specifically, the relative positioning ofthe bearing seats is able to be produced with high precision because thestamps are jointly situated in a stamping tool. Moreover, each of thebearing seats may be produced with an accurate fit. To ensure that theimpressing can be carried out in a stable manner, the stable positioningof a working plane is possible on the other side of the cover part. Theplanar outer surface areas of the cover part are provided for thispurpose.

According to example embodiments, a bearing is accommodated with aprecise fit in the respective bearing seat in each case. This isconsidered advantageous insofar as it allows for an accurate mounting.

According to example embodiments, the electric motor has a rotor shaftand a motor housing, and the rotor shaft is rotatably mounted in themotor housing with the aid of at least one bearing, an adapter flange isconnected to the motor housing in a torsion-resistant manner, thehousing of the transmission has a housing part and a cover part, whichare connected to each other, in particular, a bayonet guide region isprovided on the housing part, and the adapter flange has a lug region,in particular a bayonet nose, in particular for an engagement behind thebayonet guide region.

This offers the advantage that the motor and the transmission are ableto be connected with the aid of the bayonet connection. As a result, asimple production of the drive is possible. In addition, easierservicing can be carried out, in particular an easier exchange of themotor.

In addition, the bayonet connection may be used for centering the motorrelative to the transmission.

According to example embodiments, the adapter flange and the motorflange are integrally formed with each other, in particular as one part.This is considered advantageous insofar as it requires a lower number ofparts, which also means that less storage space is required for theproduction.

According to example embodiments, the bayonet guide region projects intoa recess of the housing part, the bayonet guide region covering a radialclearance range encompassed by the radial clearance range covered by thelug region, and thus particularly has a radially smaller extension thanthe lug region, the circumferential angular range covered by the bayonetguide region being smaller than the circumferential angular rangecovered by the recess, and the circumferential angle range covered bythe lug region being smaller in its absolute amount than the differenceof the circumferential angular range covered by the recess and thecircumferential angular range covered by the bayonet guide region, inparticular, such that the lug region is axially insertable into therecess and engages behind the bayonet guide region by a rotation. Thisoffers the advantage that the lug region provided on the adapter flangeis axially insertable into the recess, the radial clearance regioncovered by the lug region including the radial clearance region coveredby the bayonet guide region. For the simple reason that the bayonetguide region has a smaller extension than the recess in thecircumferential direction in the radial clearance range covered by thebayonet guide region, it is possible to insert the lug region into therecess so that it is able to engage behind the bayonet guide region viaits undercut section when the lug region is rotated in thecircumferential direction. The lug section thus envelops the bayonetguide region and is in such tight contact with it that it is axiallydisplaced by the bayonet guide region during a rotation in thecircumferential direction. This is accomplished as a result of acorresponding contour of the bayonet guide region.

According to example embodiments, the axial width of the bayonet guideregion increases in the circumferential direction, in particular: suchthat the lug region provided on the adapter flange is axially displacedby the bayonet guide region during a rotation in the circumferentialdirection, in particular so that the axial position is proportional tothe rotary angle position of the lug region, and/or so that the adapterflange is pressed toward the housing part when the adapter flange isrotated relative to the housing part in the in the circumferentialdirection.

This offers the advantage that an improved, i.e. a tighter, contact ofthe lug region on the bayonet guide region is achievable with the aid ofthe increasing width, thereby inducing a guidance, in particular adisplacement of the lug region in the axial direction.

According to example embodiments, a holding fin that extends from abearing receptacle of the bearing of the input shaft in the radialdirection restricts the recess in the circumferential direction.

According to example embodiments, a further holding fin which extendsfrom a bearing receptacle of the bearing of the input shaft in theradial direction restricts the recess counter to the circumferentialdirection, the bayonet guide region in particular touching the furtherholding fin, and the bayonet guide region, the further holding fin andthe bearing receptacle being provided, in particular molded, in anintegral fashion, in particular in one piece. This offers the advantagethat a stable support of the bearing receptacle is achieved. The bearingreceptacle itself is thus able to be provided with very thin walls, inparticular in an annular or hollow-cylindrical manner. The holding finsextend to a region of the housing part that is located radially fartheron the outside, so that this radially farther outwardly situated regionis provided in the manner of a frame, which improves the stability. Theframe-type region need not be provided as an actual rectangle but maypartially also be filled with material so that the stability is improvedeven further.

According to example embodiments, an elastically deformed seal issituated at the bottom of the cup-shaped bearing receptacle between thebearing receptacle and the bearing accommodated therein, and web regionsaxially project at the bottom of the bearing receptacle, against whichthe bearing is resting so that the deformation of the seal is restrictedwith the aid of the web regions, the elastically deformed seal pressingthe bearing against a step which is formed on the input shaft, the inputshaft in particular being rotatably mounted relative to the bearingreceptacle with the aid of the bearing. This offers the advantage thatthe seal presses the bearing against a step of the shaft on the one handand is able to be used as a seal on the other hand. In this context, thecontact pressure should be restricted by the web regions and noexcessive contact forces are therefore able to be generated.

According to example embodiments, the cover part also includes bearingreceptacles arranged in the shape of a cup, and holding fins extend fromthe respective bearing receptacle to a circumferential edge region ofthe cover part, axially projecting web regions are arranged on therespective bottom of the cup-shaped bearing receptacle, which restrictthe elastic deformation of a respective seal, the respective seal inparticular pressing the respective bearing against a step provided onthe respective shaft. This offers the advantage that the seal providessealing on the one hand and axially secures the bearing and presses itagainst a step of the shaft mounted by the bearing on the other hand.

According to example embodiments, a bolt braced on the housing part issituated in a recess of the housing part and in particular is axiallypressed in the direction of the adapter flange by a spring element forlocking purposes, in particular. This is considered advantageous insofaras it allows for simple locking of the bayonet connection. Anuncomplicated connection is therefore achievable with the aid of thebayonet connection, and spontaneous loosening of the bayonet connectionis prevented.

According to example embodiments, a bolt braced on the adapter flange issituated in a recess of the adapter flange and in particular is axiallypressed in the direction of the housing part by a spring element, inparticular for locking purposes. This is considered advantageous insofaras it allows for simple locking of the bayonet connection. Anuncomplicated connection is therefore achievable with the aid of thebayonet connection, and spontaneous loosening of the bayonet connectionis prevented.

According to example embodiments, web regions axially that areprojecting toward the housing part are arranged on the adapter flange,each projecting into a respective annular groove of the housing part andthus functioning as a guide during the rotary motion of the adapterflange relative to the housing part, the radial clearance region coveredby the individual web region being independent of the circumferentialangle, the respective web region in particular extending in thecircumferential direction, the web regions in particular being situatedat the same radial distance but set apart from one another in thecircumferential direction. This is considered advantageous insofar as itallows both for easy centering and guidance. An annular groove intowhich the web regions project and therefore act as a guide may be used,in particular. This is considered advantageous because the guidance andcentering are easily achievable with the aid of the web regions. This isso because the web regions on the adapter flange are arranged in themanner of a circle segment and partially project into an annular groovedeveloped on the housing part, so that a guidance comes about when thebayonet connection is operated, i.e. when the adapter flange is rotatedrelative to the housing part.

According to an example embodiment of the present invention, a methodfor producing a drive includes a first method step, in which the housingpart is produced in a casting process, a second method step, in which astamping tool is pressed into bearing receptacles of the housing part sothat precisely fitting bearing seats are produced, the stamping tool inparticular having at least two stamps, and each stamp being provided forthe molding of a respective bearing seat, and a third method step, inparticular, in which a bearing is particularly accommodated in therespective bearing seat in each case.

This offers the advantage that an uncomplicated production by a castingprocess may be used and the bearing seats are able to be placed andproduced in a highly precise manner by exerting pressure on the stampingtool.

According to example embodiments, the cover part is produced by acasting process in a first production method step, in a secondproduction method step, a stamping tool is pressed into bearingreceptacles of the cover part so that bearing seats having a precise fitare produced, the stamping tool in particular having at least twostamps, and each stamp being provided for forming a respective bearingseat, and, in particular, in a third production method step, arespective bearing is accommodated in the respective bearing seat. Thisoffers the advantage that the cover part and also the housing part maybe provided with precisely produced bearing seats.

Further features and aspects of example embodiments of the presentinvention are described in greater detail below with reference to theappended Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view of a cover part 1 of the drive according to anexample embodiment of the present invention from a first visual angle.

FIG. 2 is an oblique view of cover part 1 from a different visual angle.

FIG. 3 is a side view of cover part 1.

FIG. 4 is the drive in a part-sectional oblique view.

FIG. 5 is a sectional view of the drive, in which a bolt 50 provided forlocking purposes can be seen.

FIG. 6 is an oblique view of a housing part 40 of the drive in anoblique view.

FIG. 7 illustrates housing part 40 in an oblique view from a differentvisual angle.

FIG. 8 illustrates the drive having a transmission and an electric motorin an oblique view.

FIG. 9 illustrates the electric motor of the drive in an oblique view.

FIG. 10 is a part-sectional and oblique view of cover part 1, the visualangle roughly corresponding to the visual angle of a side view.

DETAILED DESCRIPTION

As illustrated in the Figures, in particular in FIG. 8, the drive has atransmission which is driven by an electric motor.

As illustrated in the Figures, the electric motor includes a housingpart 41, which is connected to a motor flange 42 that is connected toadapter flange 43. The housing of the transmission has a housing part 40as well as a cover part 1, which is sealingly connected to housing part40.

Adapter flange 43 is connected to housing part 40, for which purpose abayonet-type connection is used.

The stator of the electric motor is accommodated in motor housing 41 andalso bearings for mounting a rotor shaft of the electric motor. Therotor shaft is connected to input shaft 45 of the transmission with theaid of a clutch in a torsion-resistant manner. For this reason, theclutch has a first clutch part 37, which is connected to the rotor shaftin a manner that is resistant to torsion, an intermediate part 38, whichmay be produced from a plastic or elastomeric material, and a secondclutch part 39, which is connected to input shaft 45 in atorsion-resistant manner.

First clutch part 37 and second clutch part 39 may be produced frommetal, and intermediate part 38 may be produced from a material having alower hardness.

The clutch may be arranged as a dog clutch. Thus, intermediate part 38is placed between the two clutch parts (37, 39) in the circumferentialdirection. Torque shocks are able to be damped in this manner.

Connected to the input shaft in a torsion-resistant manner is a firsttoothed wheel, which is in engagement with a further toothed wheelconnected to an intermediate shaft 49 in a torsion-resistant manner. Athird toothed wheel, which is in engagement with a toothed wheel that isconnected to output shaft 48 in a torsion-resistant manner, is alsoconnected to intermediate shaft 49 in a torsion-resistant manner.

Each shaft is rotatably mounted via bearings 47, which are accommodatedeither in cover part 1 or in housing part 40.

A separate bearing receptacle (4, 5, 6) is provided on housing part 40and on cover part 1 in order to accommodate the individual bearing 47.The wall of the respective bearing receptacle (4, 5, 6) has a thinconfiguration and completely surrounds the bearing in the respectivecircumferential direction. In the axial direction, the bearingreceptacle (4, 5, 6) covers an axial range which encompasses the axialregion that is covered by the respective accommodated bearing 47 in theaxial direction.

The bearing receptacles (4, 5, 6) are integrally formed, in particularin one piece, either on housing part 40 or on cover part 1 in each case.

Using a molding tool, a cylindrical space region in which the respectivebearing 47 is accommodated and resting, is provided on the inner wall ofthe individual bearing receptacle (4, 5, 6). In the circumferentialangular ranges in which the region encompassed by the bearing receptacle(4, 5, 6) has a greater radial extension, the contact surface betweenthe bearing receptacle (4, 5, 6) and bearing 47 is interrupted.

A seal is situated between housing part 40 and a bearing receptacle (4,5, 6) formed on housing part 40, which presses bearing 47 against a stepprovided developed on the shaft mounted by this particular bearing 47.The seal is elastically deformed for this purpose, the deformation beingrestricted by respective web regions 7 that are provided on housing part40.

Web regions 7, which are formed on housing part 40 and are in contactwith the same bearing 47 in each case, are situated at the same radialdistance from the axis of rotation of the shaft mounted by this bearing47. In the circumferential direction, web regions 7 of this particularbearing 47 are set apart from one another, in particular at regularintervals.

The bearing receptacles (4, 5, 6) axially project from the rest ofhousing part 40 and/or cover part 1.

This remaining cover part 1 is arranged in the form of a trough and hasa bottom region from which the bearing receptacles (4, 5, 6) project.

An outer circumferential edge region is situated on remaining cover part1, which covers an axial region that is also covered by the bearingreceptacles (4, 5, 6).

Four holding fins 2, which are set apart from one another in thecircumferential direction, extend from this edge region to bearingreceptacle 4, which is provided for the accommodation of bearing 47 ofoutput shaft 48. The distance of holding fins 2 in the circumferentialdirection is not regular. This makes it possible to reduce resonantfrequencies.

A connecting fin 3 is set apart from holding fins 2 of bearingreceptacle 4, which is provided for the accommodation of bearing 47 ofintermediate shaft 49, and extends from bearing receptacle 4 to adjacentbearing receptacle 5.

Two further holding fins 2 are provided on cover part 1, which extendfrom bearing receptacle 5 to the edge region of cover part 1.

Bearing receptacle 6 of bearing 47 of input shaft 45, too, is stabilizedwith the aid of four holding fins 2, each extending from bearingreceptacle 6 to the edge region of cover part 1 and being set apart fromone another in the circumferential direction.

In addition, a further connecting fin 3 is provided, which extends frombearing receptacle 5 to bearing receptacle 6.

A seal is situated between accommodated bearing 47 and cover part 1, inparticular the bottom region of cover part 1, which exerts pressure inthe axial direction on respective bearing 47 so that it is pressedagainst a step of the respective shaft mounted by respective bearing 47.The elastic deformation of the seal is restricted by the web regions 7provided on cover part 1, in particular in the bottom region.

As a result, respective bearing 47 is compressed and sealed with the aidof seal 46.

Cover part 1 is connected to housing part 40 by screws and sealed, i.e.tightly connected, with the aid of an interposed seal.

As illustrated in FIG. 6, housing part 40 also has a circumferentialedge region on the outside. Housing part 40 has a bearing receptacle 4for input shaft 45, which accommodates a bearing of input shaft 45. Fourholding fins 2, which are set apart from one another in thecircumferential direction, extend from the edge region to bearingreceptacle 4 in each case, in particular so that it is stabilized, inparticular with regard to oscillations and/or transverse forcesintroduced via input shaft 45.

An axial region that encompasses the axial region covered by the bearingof input shaft 45 accommodated in housing part 40, is covered by thisedge region.

The bottom region of housing part 40 has a first and a second recess 60,which are provided for the insertion of lug regions 92, in particularbayonet noses.

First recess 60 is restricted by a first of holding fins 2 in thecircumferential direction. Second recess 60 is restricted by a second ofholding fins 2 counter to the circumferential direction.

The two other holding fins restrict the other recess 60 in thecircumferential direction and/or counter to the circumferentialdirection.

A first bayonet guide region 61 radially projects from bearing recess 4,in particular into recess 60. First bayonet guide region 61 extendsacross a smaller circumferential angular range than recess 60 and has asmaller radial extension than recess 60.

In addition, a second bayonet guide region 61 radially projects frombearing recess 4, in particular into other recess 60. Second bayonetguide region 61 also extends across a smaller circumferential angularrange than second recess 60 and also has a smaller radial extension thansecond recess 60.

A centrally disposed recess is provided on adapter flange 43, and lugregions 92, which are set apart from one another in the circumferentialdirection, project radially inward into the recess.

In the circumferential direction, each of the two lug regions 92 has asmaller extension than the difference of the extension of recess 60 andthe extension of bayonet guide region 61.

When adapter flange 43 is placed against housing part 40, the respectivelug region 92 is thus able to be inserted into the free space availablebetween the restriction of recess 60 in the circumferential direction,i.e. first holding fin 2, and bayonet guide region 61 and becomeseffective through a relative rotation of the adapter flange as anundercut behind bayonet guide region 61.

The bayonet guide region has an axial position that increases in thecircumferential direction, so that adapter flange 43 is pressed evermore closely or strongly against housing part 40 during the relativerotation. On the one hand, the rotatory motion is restricted by thecontact of adapter flange 43 with housing part 40 and on the other hand,also by second holding fin 2, which restricts the rotatory motion in thecircumferential direction.

The axial wall thickness of bayonet guide region 61 may increase in thecircumferential direction so that lug region 92 engaging behind isincreasingly displaced farther in the axial direction and adapter flange43 is therefore pressed against housing part 40.

For locking purposes, a bolt 50 is guided in a blind hole formed onhousing part 40, and a spring element 51 that is braced at the bottom ofthe blind hole presses bolt 50 in the direction of adapter flange 43.

As soon as a recess introduced into adapter flange 43 is brought intoalignment with the blind hole of housing part 40 during the rotatorymotion, bolt 50 is therefore partially pressed into the recess by springelement 51. As a result, axially aligned bolt 50 then projects into therecess of adapter flange 43 via its region that projects from housingpart 40, thereby stopping the rotatory motion.

Formed on adapter flange 43 are web regions 90 axially projecting towardhousing part 40, which project into an annular groove of housing part 40and thus act as guides during the rotatory motion. The respective webregion 90 extends in the circumferential direction, and the web regionsare disposed at the same radial distance but are set apart from oneanother in the circumferential direction.

Each one of the shafts (45, 48, 49) is mounted via two bearings, andeach bearing is axially acted upon by a seal (44, 46) so that thebearings are preloaded relative to each other. A first bearing of afirst shaft of the shafts (45, 48, 49) is accommodated in cover part 1and the other bearing of this first shaft is accommodated in housingpart 40. The first seal is accommodated in cover part 1 and pressesagainst the first bearing of the first shaft. The second seal isaccommodated in housing part 40 and presses against the second bearingof the first shaft. As a result, the first seal presses the firstbearing against a first step on the first shaft, and the second sealpresses the second bearing against a second step of the first shaft. Thebearings are therefore positioned with preloading relative to eachother. The seals may be arranged as O-rings or as flat seals in eachcase.

In order to produce precisely manufactured bearing seats for theaccommodated bearings of all shafts of the transmission, a forming toolis employed after the production by a casting process.

Cover part 1 is thus produced in a first production method step as acast component. By its outer side, i.e. by the side that faces away fromthe motor in the subsequently produced drive, cover part 1 is thenplaced on a planar surface. As illustrated in FIG. 3, cover part 1 hasplanar, i.e. level, bearing surface areas 20. As a result, cover part 1is situated on the planar surface, e.g., a work table, in a stablemanner. A stamp as a molding tool is then pressed into each one of thebearing receptacles, the stamp having a cylindrical shape. In thismanner, the bearing seats in the bearing receptacles are brought to theproper fit. The stamps for the bearing receptacles may be impressed in asynchronous manner. The relative position and alignment of the bearingseats can thus be ensured with high precision. Tilting of cover part 1when the stamping tool is impressed is thereby prevented.

Cylindrical sections 8 of the wall of the respective bearing receptacleare thus able to be produced with an accurate fit. However, thesesections are not produced in a contiguous form but are set apart fromone another in the circumferential direction. As a result, thecylindrical sections of the wall of the respective bearing receptaclealternate with respective adjacent sections that have a radially greaterextension.

The described method for the production of precisely fitting bearingseats is also executed for housing part 40. Toward this end, saidhousing part 40 has planar surface sections on the side facing the motorso that it may be placed on a planar surface in a stable manner and thestamping tools for the accurate production of the bearing seats are ableto be synchronously impressed into the bearing receptacles. Thisprevents tilting of housing part 40 when the stamping tool is pressedin. The bearing seats consequently have a precise alignment relative toone another and are also produced with a precise fit as far as theirindividual shape is concerned.

Adapter flange 43 and motor flange 42 may be integrally formed, i.e. inone piece with each other.

LIST OF REFERENCE NUMERALS

-   1 cover part-   2 holding fin-   3 connecting fin-   4 bearing receptacle-   5 bearing receptacle-   6 bearing receptacle-   7 web region-   8 cylindrical section of the wall of the bearing receptacle 4-   20 bearing surface area-   37 first clutch part-   38 intermediate part-   39 second clutch part-   40 housing part-   41 motor housing-   42 motor flange-   43 adapter flange-   44 seal-   45 input shaft-   46 seal-   47 bearing-   48 output shaft-   49 intermediate shaft-   50 bolt-   51 spring element-   60 recess for bayonet nose-   61 bayonet guide region-   90 web region-   91 rotor shaft-   92 lug region, in particular bayonet nose

The invention claimed is:
 1. A drive, comprising: an electric motorincluding a rotor shaft and a motor housing, the rotor shaft rotabtablymounted in the motor housing by at least one bearing; and a transmissionincluding a housing, the housing of the transmission having a housingpart and a cover part connected to each other, the housing partincluding a bayonet guide region being developed on the housing part;wherein an adapter flange is connected to the motor housing in atorsion-resistant manner, the adapter flange having a lug region adaptedfor an engagement behind a bayonet guide region projecting into a recessof the housing part, the recess being restricted in a circumferentialdirection by a holding fin provided on the housing part and extendingfrom a bearing receptacle of the bearing of an input shaft of thetransmission, in relation to an axial direction of the input shaft, in aradial direction; and wherein the recess is restricted counter to thecircumferential direction by a further holding fin provided on thehousing and extending from the bearing receptacle of the bearing of theinput shaft in the radial direction.
 2. The drive according to claim 1,wherein the lug region includes a bayonet nose adapted for engagementbehind the bayonet guide region projecting into the recess of thehousing part.
 3. The drive according to claim 1, wherein the bayonetguide region touches the further holding fin, the bayonet guide region,the further holding fin, and the bearing receptacle being integrallyprovided and/or molded as one part.
 4. The drive according to claim 1,wherein the adapter flange and a motor flange are integral with eachother.
 5. The drive according to claim 1, wherein the bayonet guideregion covers a radial clearance region which is encompassed by a radialclearance region covered by the lug region, and has a radially smallerextension than the lug region, a circumferential angular region coveredby the bayonet guide region being smaller than a circumferential angularregion covered by the recess, a circumferential angular region coveredby the lug region being smaller in absolute amount than a difference ofthe circumferential angular region covered by the recess and thecircumferential angular range covered by the bayonet guide region, thelug region being axially insertable into the recess and engages behindthe bayonet guide region by a rotation.
 6. The drive according to claim1, wherein an axial width of the bayonet guide region increases in acircumferential direction, the lug region provided on the adapter flangebeing axially displaced by the bayonet guide region through a rotationin the circumferential direction, so that an axial position isproportional to a rotary angle position of the lug region, and/or theadapter flange being pressed toward the housing part when the adapterflange is rotated relative to the housing part in the circumferentialdirection.
 7. The drive according to claim 1, wherein a bolt braced onthe housing part is provided in a recess of the housing part and isaxially pressed toward the adapter flange by a spring, for lockingpurposes, and/or a bolt which is braced on the adapter flange isprovided in a recess of the adapter flange, the bolt being axiallypressed toward the housing part by a spring, for locking purposes. 8.The drive according to claim 1, wherein web regions axially projectingtoward the housing part are provided on the adapter flange and projectinto a respective annular groove of the housing part and act as guidesduring rotatory motion of the adapter flange relative to the housingpart, a radial clearance region covered by a respective web region isindependent of a circumferential angle, the respective web regionextending in a circumferential direction, the web regions being arrangedat a same radial distance but being set apart from one another in thecircumferential direction.
 9. The drive according to claim 1, wherein ashaft and/or an input shaft of the transmission is mounted via thebearing as a first bearing and via a second bearing, the first bearingbeing accommodated in a bearing receptacle provided on the housing part,and the second bearing being accommodated in a bearing receptacleprovided on the cover part.
 10. The drive according to claim 1, whereinan individual seal is arranged between a respective bearing receptacleand a respective bearing, which is elastically deformable so that therespective bearing is pressed against a step of the shaft by therespective seal, so that the bearings of the shaft are preloaded withrespect to one another.
 11. The drive according to claim 10, wherein theindividual seal is made of rubber and/or an elastomer material, and/orwherein the individual seal is arranged as an O-ring.
 12. The driveaccording to claim 10, wherein web regions projecting toward the bearingare arranged on the housing part and accommodated in the bearingreceptacle, the web regions restricting elastic deformation of the seal,the web regions being arranged at a same radial distance and/or beingset apart from one another in a circumferential direction, and/or theweb regions resting against a respective bearing.
 13. The driveaccording to claim 10, wherein the seal is arranged at a bottom of acup-shaped bearing receptacle between the bearing receptacle and thebearing accommodated in the bearing receptacle, web regions axiallyprojecting at the bottom of the bearing receptacle, against which thebearing is resting so that the deformation of the seal is restrictedwith the aid of the web regions, the seal pressing the bearing against astep provided on the shaft, the shaft being rotatably mounted relativeto the bearing receptacle with the aid of the bearing.
 14. The driveaccording to claim 10, wherein cup-shaped bearing receptacles areprovided on the cover part, holding fins extend from a respectivebearing receptacle to a circumferential edge region of the cover part,and axially projecting web regions are provided on a respective bottomof a cup-shaped bearing receptacle, which restrict elastic deformationof a respective seal, the respective seal pressing the respectivebearing onto a step provided on a respective shaft.
 15. The driveaccording to claim 1, wherein the housing part has the bearingreceptacles, and a separate bearing seat is provided in each of thebearing receptacles, the respective bearing seat being interrupted in acircumferential direction, planar bearing surface areas that are alignedwith respect to one another being provided on a side facing away fromthe bearing seat of the housing part, the bearing surface areas beingprovided in a common plane.
 16. The drive according to claim 1, whereinthe cover part includes bearing receptacles, and a separate bearing seatis provided in each bearing receptacle, a respective bearing seatincluding interruptions in a circumferential direction, planar bearingsurface areas, which are aligned with one another, being arranged on theside facing away from the bearing seat of the cover part, the bearingsurface areas being provided in a common plane, and/or a respectivebearing being accommodated with a precise fit in a respective bearingseat.
 17. A method for producing a drive as recited in claim 1,comprising: casting the housing part by a casting process; pressing astamping tool into the bearing receptacle and at least one furtherbearing receptacle of the housing part so that bearing seats areproduced with an accurate fit, the stamping tool including at least twostamps, and each stamp being provided to form a respective bearing seat;and accommodating a bearing in each bearing seat.